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Hyperphosphatemia after sodium phosphate laxatives in low risk patients:Prospective study 被引量:6
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作者 Marcela Noemi Casais Guillermo Rosa-Diez +3 位作者 Susana Pérez Elina Noemi Mansilla Susana Bravo Francisco Carlos Bonofiglio 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第47期5960-5965,共6页
AIM:To establish the frequency of hyperphosphate-mia following the administration of sodium phosphate laxatives in low-risk patients. METHODS:One hundred consecutive ASAⅠ-Ⅱindividuals aged 35-74 years,who were under... AIM:To establish the frequency of hyperphosphate-mia following the administration of sodium phosphate laxatives in low-risk patients. METHODS:One hundred consecutive ASAⅠ-Ⅱindividuals aged 35-74 years,who were undergoing colonic cleansing with oral sodium phosphate(OSP) before colonoscopy were recruited for this prospective study.Exclusion criteria:congestive heart failure, chronic kidney disease,diabetes,liver cirrhosis,intestinal obstruction,decreased bowel motility,increased bowel permeability,and hyperparathyroidism.The day before colonoscopy,all the participants entered a 24-h period of diet that consisted of 4 L of clear fluids with sugar or honey and 90 mL(60 g)of OSP in two 45-mL doses,5 h apart.Serum phosphate was measured before and after the administration of the laxative. RESULTS:The main demographic data(mean±SD) were:age,58.9±8.4 years;height,163.8±8.6 cm; weight,71±13 kg;body mass index,26±4;women, 66%.Serum phosphate increased from 3.74±0.56 to 5.58±1.1 mg/dL,which surpassed the normal value (2.5-4.5 mg/dL)in 87%of the patients.The highest serum phosphate was 9.6 mg/dL.Urea and creatinine remained within normal limits.Post-treatment OSP se-rum phosphate concentration correlated inversely with glomerular filtration rate(P<0.007,R 2=0.0755),total body water(P<0.001,R 2=0.156)and weight(P< 0.013,R 2=0.0635). CONCLUSION:In low-risk,well-hydrated patients, the standard dose of OSP-laxative-induced hyperphos-phatemia is related to body weight. 展开更多
关键词 Bowel preparation Colonic cleansing COLONOSCOPY HYPERPHOSPHATEMIA laxatives Sodium phosphate Preoperative evaluation DEHYDRATION
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Review of efficacy and safety of laxatives use in geriatrics 被引量:5
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作者 Manhal Izzy Anju Malieckal +1 位作者 Erin Little Sury Anand 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2016年第2期334-342,共9页
AIM:To study the efficacy and safety of pharmacolo-gical treatment of constipation in geriatrics.METHODS:Pub Med,MEDLINE,google scholar,and Ovid were searched to identify human studies performed on the use of laxative... AIM:To study the efficacy and safety of pharmacolo-gical treatment of constipation in geriatrics.METHODS:Pub Med,MEDLINE,google scholar,and Ovid were searched to identify human studies performed on the use of laxatives in elderly with constipation,which were conducted between January1990 and January 2013 using the specified keywords.Controlled studies that enrolled geriatric patients with a diagnosis of constipation and addressed the efficacy and/or the safety of pharmacological treatments were included.Studies were excluded from this review if they were non-controlled trials,case series,or case reports.RESULTS:Out of twenty three studies we initially retrieved in our search,only nine studies met the eligibility criteria of being controlled trials within geriatrics.The laxatives examined in the nine studies were senna,lactulose,sorbital,polyethylene glycol(PEG),lubiprostone,linaclotide,and prucalopride.In those studies,senna combinations had a higher efficacy than sorbitol or lactulose as well as,a very good adverse effect profile.PEG was also shown to be safe and effective in geriatric population.Furthermore,it has been shown that PEG is as safe in geriatrics as in general population.New agents like lubiprostone and prucalopride show promising results but the data about these agents in geriatrics are still limited which warrant further investigation.CONCLUSION:Senna combinations and PEG appear to have a more favorable profile over the other traditionally used laxatives in elderly patients with constipation. 展开更多
关键词 Chronic CONSTIPATION laxatives ELDERLY LUBIPROSTONE Linaclotide PRUCALOPRIDE
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Effects of Prophylactic Laxatives for Opioid-Induced Constipation on Constipation Severity and Quality of Life among Patients with Cancer
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作者 Mohammad Al-Naeem Mohammad Ibrahim Al Qadire Jafar Alasad 《Open Journal of Nursing》 2018年第8期505-517,共13页
Background: To reduce patients’ unnecessary suffering, Opioids Induced Constipation (OIC) should be identified and treated as early as possible with the most current treatment. Aims: to investigate the effectiveness ... Background: To reduce patients’ unnecessary suffering, Opioids Induced Constipation (OIC) should be identified and treated as early as possible with the most current treatment. Aims: to investigate the effectiveness of prophylactic laxatives in reducing the severity of OIC and its impact on cancer patients’ quality of life. Methods: A Randomized Clinical Trial design was used. 57 cancer patients from one oncology clinic at a governmental hospital participated in the study. Patients in the intervention groups were given an oral colonic stimulant laxative (i.e. Bisacodyl, Dose = 3 tab/day) or an oral colonic osmotic laxative (i.e. Lactulose, Dose = 15 ml three times per day), while patients in the control continue receiving their routine care as usual. Results: A significant decrease in the severity of constipation symptoms among the intervention group at four weeks post-intervention was noted (p Conclusions: It can be concluded that the use prophylactic of first line laxatives concurrently with opioids decreased the severity of OIC and improved the QOL for cancer patients. 展开更多
关键词 NEOPLASM Adult OPIOIDS CONSTIPATION STIMULANT laxatives
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Choice of laxatives and colonoscopic preparation in pregnant patients from the viewpoint of obstetricians and gastroenterologists 被引量:4
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作者 Jeevan Vinod Jennifer Bonheur +1 位作者 Burton I Korelitz Georgia Panagopoulos 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第48期6549-6552,共4页
AIM: To elucidate the preferences of gastroenterologists at our institution and compare them to those of obstetricians when making decisions in the pregnant patient, including which type of bowel preparations to use ... AIM: To elucidate the preferences of gastroenterologists at our institution and compare them to those of obstetricians when making decisions in the pregnant patient, including which type of bowel preparations to use for flexible sigmoidoscopy or colonoscopy, as well as which laxatives can be used safely.METHODS: Surveys were mailed to all attending gastroenterologists (n = 53) and obstetricians (n = 99) at our institution. Each survey consisted of the 14 most common laxative or motility agents used in pregnancy and inquired about the physician's prescribing habits in the past as well as their willingness to prescribe each medication in the future. The survey also listed four common bowel preparations used prior to colonoscopy and sigmoidoscopy and asked the physician to rank the order of the preferred agent in each case.RESULTS: With regard to common laxatives, both gastroenterologists and obstetricians favor the use of Metamucil, Colace, and Citrucel. Both groups appear to refrain from using Fleets Phosphosoda and Castor oil. Of note, obstetricians are less inclined to use PEG solution and Miralax, which is not the case ,with gastroenterologists. In terms of comparing bowel preparations for colonoscopy, 50% of gastroenterologists prefer to use PEG solution and 50% avoid the use of Fleets Phosphosoda. Obstetricians seem to prefer Fleets Phosphosoda (20%) and tend to avoid the use of PEG solution (26%). With regard to bowel preparation for sigmoidoscopy, both groups prefer Fleets enema the most (51%), while magnesium citrate is used least often (38%).CONCLUSION: It is clear that preferences in the use of bowel cleansing preparations between the two groups exist, but there have not been many case controlled human studies in the pregnant patient that give clear cut indications for using one versus another drug. In light of the challenge of performing controlled trials in pregnant women, more extensive surveys should be undertaken to gather a larger amount of data on physicians' experiences and individual preferences. 展开更多
关键词 LAXATIVE Pregnancy COLONOSCOPY SIGMOIDOSCOPY Gastroenterologists OBSTETRICIANS
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Diphenyl methane laxatives do not induce electrolyte imbalance
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作者 Stefan Müller-Lissner 《Open Journal of Gastroenterology》 2013年第5期272-275,共4页
Aim: To analyse whether there are changes in sodium and potassium serum levels during chronic treatment with the diphenyl methanes bisacodyl and sodium picosulfate. Methods: A literature search was done using PubMed, ... Aim: To analyse whether there are changes in sodium and potassium serum levels during chronic treatment with the diphenyl methanes bisacodyl and sodium picosulfate. Methods: A literature search was done using PubMed, and the reference lists of pertinent papers were screened for additional studies. Only studies of at least 4 weeks duration were considered for further analysis. Results: Four relevant studies were identified. In three randomised controlled trials with 5 to 10 mg daily of bisacodyl or sodium picosulfate, respectively, over four weeks no electrolyte losses were found. Hypokalemia was also not a problem in a group of patients with paraplegia using bisacodyl suppositories for 2 to 34 years. Conclusions: Electrolyte losses, particularly hypokalemia, are not a problem when bisacodyl or sodium picosulfate are used long-term. 展开更多
关键词 LAXATIVE BISACODYL Sodium Picosulfate HYPONATREMIA HYPOKALEMIA
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Successful treatment of small bowel phytobezoar using double balloon enterolithotripsy combined with sequential catharsis:A case report
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作者 Bing-Yun Lu Zhi-Yu Zeng Dong-Jing Zhang 《World Journal of Radiology》 2024年第11期683-688,共6页
BACKGROUND Small bowel bezoar obstruction(SBBO)is a rare clinical condition characterized by hard fecal masses in the small intestine,causing intestinal obstruction.It occurs more frequently in the elderly and bedridd... BACKGROUND Small bowel bezoar obstruction(SBBO)is a rare clinical condition characterized by hard fecal masses in the small intestine,causing intestinal obstruction.It occurs more frequently in the elderly and bedridden patients,but can also affect those with specific gastrointestinal dysfunctions.Diagnosing SBBO is challenging due to its clinical presentation,which mimics other intestinal obstructions.While surgical intervention is the typical treatment for SBBO,advancements in endo-scopic techniques have led to increased use of non-surgical methods,such as endoscopic lithotripsy.CASE SUMMARY We report a case of small bowel obstruction induced by a phytobezoar.A 49-year-old male with a history of type 2 diabetes and long-term persimmon consumption presented to the hospital with symptoms of vomiting,abdominal distension,and constipation.Computed tomography revealed a small bowel obstruction with foreign bodies.Double balloon enteroscopy identified a phytobezoar blocking the intestinal lumen.The bezoar was successfully fragmented using a snare,and the fragments were treated with 100 mL of paraffin oil to facilitate their passage.This case report aims to enhance the understanding of this rare condition by detailing the clinical presentation,diagnostic process,and treatment outcomes of a patient with SBBO.Special attention is given to the application and effectiveness of non-surgical treatment methods,along with strategies to optimize patient manage-ment.CONCLUSION Double balloon enteroscopy combined with sequential laxative therapy is an effective approach for the treatment of a breakable phytobezoar. 展开更多
关键词 Intestinal obstruction Double balloon enteroscopy PHYTOBEZOAR Paraffin oil laxatives Case report
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α-螺旋蛋白中三分量高阶非线性薛定谔方程的怪波解
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作者 王梦雅 陈婷婷 王立洪 《宁波大学学报(理工版)》 2024年第1期20-30,共11页
以三分量高阶非线性薛定谔方程为α-螺旋蛋白中生物能量沿蛋白质分子链传输的控制方程,研究三个相互耦合的波函数在极限状态下激发的怪波.基于控制模型的Lax对表示,利用规范变换得到了达布变换的行列式形式.通过Lax对的变量分离和平移... 以三分量高阶非线性薛定谔方程为α-螺旋蛋白中生物能量沿蛋白质分子链传输的控制方程,研究三个相互耦合的波函数在极限状态下激发的怪波.基于控制模型的Lax对表示,利用规范变换得到了达布变换的行列式形式.通过Lax对的变量分离和平移参数的引入,给出了怪波激发的代数条件.进一步利用幂级数的多项分裂构造怪波解的基础特征函数,并由此导出退化的达布变换.最后通过退化的达布变换获得怪波解,并在不同参数下,用三维图形示例怪波的波形演化及其极值轨迹. 展开更多
关键词 三分量高阶非线性薛定谔方程 LAX对 达布变换 怪波
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五阶耦合扩展mKdV方程的N阶孤子解
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作者 刘亚停 文竹妍 +1 位作者 魏周超 宋妮 《动力学与控制学报》 2024年第9期24-28,共5页
基于二分量五阶耦合扩展修正的Korteweg-de Vries(mKdV)方程,借助广义Darboux变换和Taylor展式,得到方程N阶孤子解的迭代表达式.对谱参数的实部和虚部分类讨论,取合适的自由参数,通过数值模拟展示孤子间的相互作用图,进一步分析不同参... 基于二分量五阶耦合扩展修正的Korteweg-de Vries(mKdV)方程,借助广义Darboux变换和Taylor展式,得到方程N阶孤子解的迭代表达式.对谱参数的实部和虚部分类讨论,取合适的自由参数,通过数值模拟展示孤子间的相互作用图,进一步分析不同参数对孤子间弹性及非弹性碰撞的影响.所得结果对高阶孤子的研究具有一定的理论意义. 展开更多
关键词 广义Darboux变换 LAX对 MKDV方程 孤子解
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Jimbo-Miwa-Like方程的Lax可积性研究
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作者 张晓乐 套格图桑 《内蒙古师范大学学报(自然科学汉文版)》 CAS 2024年第1期27-37,共11页
基于双Bell多项式方法,将Jimbo-Miwa-Like方程化为双线性形式,运用Bell多项式的相关性质,构造出方程的双Bell多项式B?cklund变换、双线性B?cklund变换、Lax对、无穷守恒律和孤子解。运用试探函数法和符号计算软件Mathematica获得方程的... 基于双Bell多项式方法,将Jimbo-Miwa-Like方程化为双线性形式,运用Bell多项式的相关性质,构造出方程的双Bell多项式B?cklund变换、双线性B?cklund变换、Lax对、无穷守恒律和孤子解。运用试探函数法和符号计算软件Mathematica获得方程的复合型解,并选取适当的参数,绘制一部分精确解的图像来说明性质。 展开更多
关键词 Bell多项式方法 B?cklund变换 LAX对 无穷守恒律 试探函数法
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Higher-dimensional Chen-Lee-Liu equation and asymmetric peakon soliton
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作者 韩巧红 贾曼 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期224-229,共6页
Integrable systems play a crucial role in physics and mathematics.In particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integra... Integrable systems play a crucial role in physics and mathematics.In particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher dimensions.Recent studies have shown that abundant higher-dimensional integrable systems can be constructed from(1+1)-dimensional integrable systems by using a deformation algorithm.Here we establish a new(2+1)-dimensional Chen-Lee-Liu(C-L-L)equation using the deformation algorithm from the(1+1)-dimensional C-L-L equation.The new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the(1+1)-dimension.It is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original C-L-L equation and its reciprocal transformation.The traveling wave solutions are derived in implicit function expression,and some asymmetry peakon solutions are found. 展开更多
关键词 higher dimensional Chen-Lee-Liu equation Lax integrable system deformation algorithm implicit traveling wave solutions
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椭圆链式KP系统的可积性分析
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作者 王辛乙 《理论数学》 2024年第5期219-225,共7页
我们以前已经深入研究了求解椭圆链式KP方程的直接线性化方法,而求解该方程的柯西矩阵方法只是近年来的一个热门主题。本文将讨论基于柯西矩阵方法的椭圆链式KP方程的可积性,为下一步的求解做准备。本文首先从辅助向量u(2i)=(IXC)−1Pic... 我们以前已经深入研究了求解椭圆链式KP方程的直接线性化方法,而求解该方程的柯西矩阵方法只是近年来的一个热门主题。本文将讨论基于柯西矩阵方法的椭圆链式KP方程的可积性,为下一步的求解做准备。本文首先从辅助向量u(2i)=(IXC)−1Pic出发得到椭圆链式KP系统的lax组,然后从Lax组中推导出椭圆链式KP系统来完成闭环。 展开更多
关键词 椭圆链式KP系统 Lax组 柯西矩阵法
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一个负阶广义AKNS系统
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作者 朱晨迪 康静 闵卓凡 《纯粹数学与应用数学》 2024年第4期606-616,共11页
本文提出了一个与4×4矩阵谱问题相联系的新的负阶广义AKNS方程族.此方程族的典型方程是一个四分量负阶广义AKNS系统.本文给出了此四分量系统的Lax对及其达布变换.利用达布变换,构造出了此四分量负阶广义AKNS系统的孤子解,包括亮孤... 本文提出了一个与4×4矩阵谱问题相联系的新的负阶广义AKNS方程族.此方程族的典型方程是一个四分量负阶广义AKNS系统.本文给出了此四分量系统的Lax对及其达布变换.利用达布变换,构造出了此四分量负阶广义AKNS系统的孤子解,包括亮孤子解,暗孤子解及其相互作用. 展开更多
关键词 负阶AKNS方程 LAX对 达布变换 孤子解
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Current Status of Clinical Application and Basic Research on Draba nemerosa Hebecarpa Jujube Lung-Diarrhoea Soup
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作者 Yong Fan 《Journal of Biosciences and Medicines》 2024年第5期144-153,共10页
The clinical application and basic research of Draba nemerosa Hebecarpa jujube diarrhoea lung soup focus on respiratory diseases and circulatory diseases, and its clinical application is more compared with the basic r... The clinical application and basic research of Draba nemerosa Hebecarpa jujube diarrhoea lung soup focus on respiratory diseases and circulatory diseases, and its clinical application is more compared with the basic research, and Draba nemerosa Hebecarpa jujube diarrhoea lung soup is mostly used in the form of “Draba nemerosa Hebecarpa Hebecarpa jujube diarrhoea lung soup with additional subtractions or other formulas combining Draba nemerosa Hebecarpa Hebecarpa Hebecarpa jujube diarrhoea lung soup” in the clinical application. This article will focus on the main mechanisms of Draba nemerosa Hebecarpa jujube diarrhoea lung soup and its main components in the treatment of respiratory and circulatory diseases, and will give a review of the basic research on Draba nemerosa Hebecarpa Hebecarpa jujube diarrhoea lung soup as follows. 展开更多
关键词 Draba nemerosa Hebecarpa Jujube Laxative Lung Soup Clinical Application Basic Research
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An Eight Component Integrable Hamiltonian Hierarchy from a Reduced Seventh-Order Matrix Spectral Problem
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作者 Savitha Muthanna Wen-Xiu Ma 《Journal of Applied Mathematics and Physics》 2024年第6期2102-2111,共10页
We present an eight component integrable Hamiltonian hierarchy, based on a reduced seventh order matrix spectral problem, with the aim of aiding the study and classification of multicomponent integrable models and the... We present an eight component integrable Hamiltonian hierarchy, based on a reduced seventh order matrix spectral problem, with the aim of aiding the study and classification of multicomponent integrable models and their underlying mathematical structures. The zero-curvature formulation is the tool to construct a recursion operator from the spatial matrix problem. The second and third set of integrable equations present integrable nonlinear Schrödinger and modified Korteweg-de Vries type equations, respectively. The trace identity is used to construct Hamiltonian structures, and the first three Hamiltonian functionals so generated are computed. 展开更多
关键词 Matrix Spectral Problem Zero Curvature Equation Lax Pair Integrable Hierarchy NLS Equations mKdV Equations Hamiltonian Structure Lie Bracke
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获得非线性演化方程Backlund变换的一种新的途径 被引量:27
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作者 范恩贵 张鸿庆 《应用数学和力学》 CSCD 北大核心 1998年第7期603-608,共6页
本文给出一种求非线性演化方程Backlund变换的方法,应用于非线性演化方程时,得到了与WTC方法一致的Backlund变换,避开了WTC方法涉及到的递推关系和截尾的讨论·
关键词 非线性演化方程 BACKLUND变换 LAX表示
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利用CODEHOP和iCODEHOP设计简并引物克隆芒果LAX基因家族片段 被引量:10
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作者 李运合 孙光明 《热带作物学报》 CSCD 2011年第12期2278-2282,共5页
详细介绍采用CODEHOP和iCODEHOP设计简并引物的方法,并利用这2个程序设计了8对简并引物,从芒果子叶中扩增到8条不同长度的cDNA片段,测序结果表明,这些片段包含4类不同的DNA序列。经过在NCBI上进行blastx分析,这些序列与其它植物的LAX基... 详细介绍采用CODEHOP和iCODEHOP设计简并引物的方法,并利用这2个程序设计了8对简并引物,从芒果子叶中扩增到8条不同长度的cDNA片段,测序结果表明,这些片段包含4类不同的DNA序列。经过在NCBI上进行blastx分析,这些序列与其它植物的LAX基因具有高度同源性,因此推测,芒果中的LAX基因家族其至少包括4条同源基因。研究结果表明CODEHOP和iCODEHOP设计的简并引物可信性强并具有高效性。 展开更多
关键词 芒果 LAX基因 简并引物 iCODEHOP 克隆
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Consensus statement AIGO/SICCR diagnosis and treatment of chronic constipation and obstructed defecation(Part Ⅱ:Treatment) 被引量:33
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作者 Antonio Bove Massimo Bellini +9 位作者 Edda Battaglia Renato Bocchini Dario Gambaccini Vincenzo Bove Filippo Pucciani Donato Francesco Altomare Giuseppe Dodi Guido Sciaudone Ezio Falletto Vittorio Piloni 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第36期4994-5013,共20页
The second part of the Consensus Statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery reports on the treatment of chronic constipation and obstructed defecati... The second part of the Consensus Statement of the Italian Association of Hospital Gastroenterologists and Italian Society of Colo-Rectal Surgery reports on the treatment of chronic constipation and obstructed defecation. There is no evidence that increasing fluid intake and physical activity can relieve the symptoms of chronic constipation. Patients with normal-transit constipation should increase their fibre intake through their diet or with commercial fibre. Osmotic laxatives may be effective in patients who do not respond to fibre supplements. Stimulant laxatives should be re- served for patients who do not respond to osmotic laxatives. Controlled trials have shown that serotonin- ergic enterokinetic agents, such as prucalopride, and prosecretory agents, such as lubiprostone, are effec- tive in the treatment of patients with chronic constipa- tion. Surgery is sometimes necessary. Total colectomy with ileorectostomy may be considered in patients with slow-transit constipation and inertia coil who are resistant to medical therapy and who do not have defecatory disorders, generalised motility disorders or psychological disorders. Randomised controlled trials have established the efficacy of rehabilitative treat- ment in dys-synergic defecation. Many surgical proce- dures may be used to treat obstructed defecation in patients with acquired anatomical defects, but none is considered to be the gold standard. Surgery should be reserved for selected patients with an impaired quality of life. Obstructed defecation is often associated with pelvic organ prolapse. Surgery with the placement of prostheses is replacing fascial surgery in the treatment of pelvic organ prolapse, but the efficacy and safety of such procedures have not yet been established. 展开更多
关键词 laxatives PROKINETICS BIOFEEDBACK Pelvicfloor rehabilitation Outlet obstruction Stapled trans-anal rectal resection Delorme operation COLECTOMY Pelvic organ prolapse Mesh
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(Bi_(4-x),La_x)Ti_3O_(12)铁电陶瓷性能研究 被引量:3
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作者 申林 肖定全 +2 位作者 余萍 朱建国 高道江 《压电与声光》 CAS CSCD 北大核心 2002年第3期199-201,共3页
采用溶胶 -凝胶 (Sol- Gel)技术制备了 (Bi4 - x,L ax) Ti3O1 2 (BL T)干凝胶粉体 ,并用此粉体制备了陶瓷。利用 XRD、SEM等手段分析表征了陶瓷的结构、表面形貌及介电性能。结果表明 ,采用本文工艺技术制备的陶瓷为类钙钛矿结构 ,表面... 采用溶胶 -凝胶 (Sol- Gel)技术制备了 (Bi4 - x,L ax) Ti3O1 2 (BL T)干凝胶粉体 ,并用此粉体制备了陶瓷。利用 XRD、SEM等手段分析表征了陶瓷的结构、表面形貌及介电性能。结果表明 ,采用本文工艺技术制备的陶瓷为类钙钛矿结构 ,表面致密 ,陶瓷的极化场强约为 4 .5 k V/ m m;BL T陶瓷介电性能为 :介电常数 ε=4 2 5 (1k Hz) ,介电损耗 tanδ=0 .0 5 (1k Hz)。掺杂量的研究表明 ,当 x≥ 0 .4时 ,L a的引入对介电常数和介电损耗有较大的影响 ,即使介电常数升高 ,介电损耗降低。 展开更多
关键词 (Bi4-x Lax)Ti3O12 SOL-GEL 铁电陶瓷
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Tu方程族的高阶双约束流的分离变量(英文) 被引量:5
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作者 曾云波 曹昕 《数学进展》 CSCD 北大核心 2002年第2期135-147,共13页
本文给出了 Tu方程族的高阶双约束流,其自由度为 ZN+l.根据通常的办法,利用 Lax矩阵仅能引入N+l对标难分离变量和N+l个分离变量方程.本文构造出另外N对分离变量及N个分离变量方程.此外,还建立了双约束流和Tu... 本文给出了 Tu方程族的高阶双约束流,其自由度为 ZN+l.根据通常的办法,利用 Lax矩阵仅能引入N+l对标难分离变量和N+l个分离变量方程.本文构造出另外N对分离变量及N个分离变量方程.此外,还建立了双约束流和Tu方程族的Jacobi反演问题. 展开更多
关键词 Tu方程族 高阶 分离变量 双约束流 Jacobi反演问题 LAX表示 Lax矩阵
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积分型Darboux变换 被引量:7
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作者 程艺 阿妹 《数学年刊(A辑)》 CSCD 北大核心 1999年第6期667-672,共6页
Darboux变换是求解孤立子方程的有力工具,针对方程的特殊性(如与方程相联系的Lax对受到某种限制)需建立相应的Darboux变换本文通过引进一种新的积分型Darboux变换,用来求解一类Lax对为反自共轭算子的孤... Darboux变换是求解孤立子方程的有力工具,针对方程的特殊性(如与方程相联系的Lax对受到某种限制)需建立相应的Darboux变换本文通过引进一种新的积分型Darboux变换,用来求解一类Lax对为反自共轭算子的孤立子方程。 展开更多
关键词 DARBOUX变换 孤立子方程 精确解 LAX对 积分型
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